A pulsed ruby laser rangefinder is installed on one of the test ranges at the U. S. Naval Ordnance Test Station, China Lake, California, and is being evaluated for use in data acquisition for determining trajectories of airborne targets. Pulse repetition frequencies up to 10 per second for meaningful data from high speed targets, and digital range readout are con-sidered important characteristics of this equipment. This paper presents some of the pertinent constructional details, performance goals, and some test data indicative of the degree to which these goals have been met. Certain operational difficulties are pointed out and analyzed and remedial steps proposed.
A photo-optical system has been developed for determining the velocity of a projectile after ta?get penetration and the simultaneous observation of ballistic phenomena. This system pro vides a wide field of view and overcomes the difficulties introduced by light from the projectile-target impact and by the pretriggering of velocity-measuring transducers by particles broken from the target. This system enables the measurement of residual velocity with an error of only 1 to 2 percent and, at the same time, permits the observation of size, shape, distribution of other particles and distortion of the projectile.
This paper discusses the use of a vidicon storage tube in scan converter operations. It outlines the design considerations and pertinent characteristics of devices employing the storage vidicon in scan converter applications. It discusses optics, transfer characteristics and sensitivity considerations. It discusses the significant factors in choosing tube type, sweep circuits, and other associated electronics when assembling a special purpose instrument. It outlines modifications and operating techniques when utilizing an ordinary TV camera. Instruments designed and built by NOLC, both a general purpose laboratory instrument and an airborne unit, are described. The paper concludes by giving a number of example applications.
Measurement of the angle between a missile's axis as recorded on film vs. a zero reference is accomplished with an instrument employing mechanical electronic and optical means. Repeatable accuracy of 0.01 degree is predicted.
One of the graphs I presented in a recent paper' has been found to be of particular value in systems analysis where the trade-off between film speed and target brightness with lens aperture and shutter speed is to be determined. Since that graph was presented, it has become the practice to express film speed in the 0.6 gamma speed for aerial film use rather than in the ASA numbers that apply to amateur photography. The change in the number value assigned to film speed thus needs to be incorporated with the parameter chart and this is what I propose to do in this article. At the same time, I wish to present a simple explanation of how the chart works. First let us assume that the exposure equation is correct, as indeed it had better be or all of photography is in a fair amount of trouble. In the old familiar form the exposure equation is: